Tajima Kosuke, Sasaki Takashi, Yamanaka Kazuyoshi
Department of Orthopaedic Surgery, Saiseikai Kanagawaken Hospital, Yokohama, Kanagawa Prefecture, Japan 221-0821.
Hand Surg. 2005;10(2-3):279-84. doi: 10.1142/S0218810405002681.
Locking of the metacarpophalangeal (MP) joint of the fingers, though reported infrequently, is not rare in the literature. We will report two rare cases of the MP joint of the thumb locked in 90 degrees of flexion (vertical locking). The first case is a 21-year-old man, punched on his right thumb by his friend, who arrived with his thumb fixed in a flexed position. The X-ray images of the right thumb showed the proximal phalanx subluxation in the palmer side in a vertical position. The second case is a 35-year-old woman with her right thumb accidentally caught in the chain of a key-holder. The locking was easily reduced without anaesthesia in both cases. We assume the mechanism was that the flexion force on the MP joint led to subluxation and the locking occurred due to the tension of the collateral ligament caused by the volar prominence of the radial condyle.
手指掌指（MP）关节的锁定，尽管报道较少，但在文献中并不罕见。我们将报告两例罕见的拇指MP关节锁定在90度屈曲位（垂直锁定）的病例。第一例是一名21岁男性，被朋友击打右手拇指，就诊时拇指固定于屈曲位。右手拇指的X线片显示近节指骨在垂直位向掌侧半脱位。第二例是一名35岁女性，右手拇指意外被钥匙扣链条卡住。两例均在未麻醉的情况下轻松解除锁定。我们推测其机制是MP关节上的屈曲力导致半脱位，而锁定是由于桡骨髁掌侧突出导致侧副韧带紧张所致。
